The Diamond Of Darkhold

As the Builders finish the city of Ember in the middle of the 21st century, the chief builder decides to leave a helpful device for the people who will someday emerge from the underground haven. He chooses a recent invention to lock in a steel-lined vault inside the mountain near Ember’s exit. He plans for Directions for Use to accompany the device; a timer will unlock the vault at the right time. 

However, the Disaster for which the Builders created Ember—global war followed by “plagues and famines and floods” (3)—occurs 50 years later than expected; those living in Ember stay there longer than expected, too, and do not notice the vault when they finally leave. Eventually, a roamer finds the unlocked vault and takes the Directions for Use and the device. Unable to read, however, this man expects to trade the book or use it as kindling.

After a day spent sorting and piling building materials, 13-year-old Doon Harrow is grateful for quitting time. It is almost dark, and a storm is nearing. He calls for his father, who is working on the same assigned task. They live in the Pioneer Hotel just outside of Sparks, where the village leaders placed most people from Ember when they first arrived from their underground city.